The invention relates to the field of supporting devices for footwear to prevent or minimize the risk of sprained ankles.
Prior art devices and methods for minimizing the risk of sprained ankles include taping of the ankle to immobilize it against internal rotation, or excessive internal rotation, which is the cause of most ankle sprains. Very few injuries to the muscles and tendons of the ankle occur from external rotation of the ankle, or turning of the foot outwardly which is also known as eversion or supination. Inward turning of the foot and internal rotation of the ankle is referred to as inversion or pronation.
Taping of the ankles of athletes is a time consuming and rather expensive procedure. It cannot be done properly by the athlete himself. A trainer with special knowledge of how to tape ankles properly is required in order to do that job in a way that will be reasonably effective in protecting the athlete's ankle.
Attempts have been made to incorporate support members and braces into shoes, but those known to the prior art have not been successful in preventing the internal rotation of the ankle which is the basic cause of ankle sprain. An illustrative example of prior art devices of this kind is shown in U.S. Pat. No. 4,411,077, which uses two elastic straps. However, the use of elastic straps permits the ankle to still rotate internally whereby sprain can still result. The present invention uses an inelastic non-stretchable strap which effectively prevents internal rotation of the ankle that may result in a sprain. The strap in this prior art patent is also anchored to the lateral aspect or outwardly facing side of the shoe at a location and for a distance that is not effective, or less effective in preventing ankle sprains than the present invention. The outer support panel of the present invention is secured along its bottom edge to a lower side edge of the lateral aspect of the shoe between approximately mid-heel forwardly to the point on the shoe which is adjacent the distal joint of the wearer's fifth metatarsal. This arrangement provides effective protection and anchoring points at the back and the front of such outer support panel for the inelastic strap to be properly placed against the inwardly facing side of the ankle, specifically against the medial malleolus of the tibia, in a direction substantially parallel to the sole of the shoe and the wearer's foot.
Another example of prior art attempts to solve problems by incorporating support members in a shoe is illustrated in U.S. Pat. No. 3,327,410. It discloses two strap members anchored to opposite sides of the sole on the inside of the shoe, but the opposite or free ends of the straps are merely wrapped around the leg in the ankle region and secured at that point rather than being anchored to the sole, or a panel or other part of the shoe which is anchored to the sole or bottom part of the shoe. Straps which are wrapped tightly around the leg and ankle also tend to cut off blood circulation, and furthermore impede flexation of the foot and ankle in other directions.
The present invention effectively solves these problems which are present with prior art devices. If effectively immobilizes the ankle against internal rotation, while at the same time leaving the foot and ankle free to move and flex in all of the other directions necessary during active play in athletic events and while engaging in other activities.